Molecular characterization of a beta-globin gene deletion of 1357 bp in a Taiwanese beta-thalassemia carrier.
A 30-year-old male had hypochromic microcytosis and elevated Hb F and Hb A(2) levels (MCV 72.5 fL, MCH 25.2 pg, Hb F 8.9% and Hb A(2) 6.6%). Direct DNA sequencing of the entire beta-globin gene revealed no anomalies. Multiplex ligation-dependent probe amplification (MLPA) showed reduced signals at probes for the promoter, 5'UTR (5' untranslated region), exon 2 and intron 2 regions of the beta-globin gene. Gap-polymerase chain reaction (gap-PCR) successfully obtained junctional fragments. Direct sequencing of the gap-PCR product revealed that the 5' breakpoint was located at -548 (relative to the Cap site of the beta-globin gene) and the 3' breakpoint was located at +810 in the second intron of the beta-globin gene. A total of 1357 bp were deleted (NG_000007.3:g.69997_71353del1357). Similar to another two beta-globin gene deletions reported in Black and Croatian thalassemia carriers, respectively, this deletion was the result of a non homologous breakage and reunion event.
Huang
Chien-Hao
CH
GenePhile BioScience Laboratory, Ko's Obstetrics and Gynecology, Taipei, Taiwan.
Chang
Yih-Yuan
YY
Chen
Chung-Hsiung
CH
Ko
Tsang-Ming
TM
D000328:Adult; D001483:Base Sequence; D004252:DNA Mutational Analysis; D017353:Gene Deletion; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D013624:Taiwan; D055544:beta-Globins / Q000235:genetics*; D017086:beta-Thalassemia / Q000235:genetics*
D055544:beta-Globins